| /* |
| * Copyright (C) 2011 The Android Open Source Project |
| * |
| * Licensed under the Apache License, Version 2.0 (the "License"); |
| * you may not use this file except in compliance with the License. |
| * You may obtain a copy of the License at |
| * |
| * http://www.apache.org/licenses/LICENSE-2.0 |
| * |
| * Unless required by applicable law or agreed to in writing, software |
| * distributed under the License is distributed on an "AS IS" BASIS, |
| * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. |
| * See the License for the specific language governing permissions and |
| * limitations under the License. |
| */ |
| |
| #include "mutex.h" |
| |
| #include <errno.h> |
| #include <sys/time.h> |
| |
| #include "android-base/stringprintf.h" |
| |
| #include "base/atomic.h" |
| #include "base/logging.h" |
| #include "base/systrace.h" |
| #include "base/time_utils.h" |
| #include "base/value_object.h" |
| #include "mutex-inl.h" |
| #include "scoped_thread_state_change-inl.h" |
| #include "thread-inl.h" |
| |
| namespace art { |
| |
| using android::base::StringPrintf; |
| |
| static Atomic<Locks::ClientCallback*> safe_to_call_abort_callback(nullptr); |
| |
| Mutex* Locks::abort_lock_ = nullptr; |
| Mutex* Locks::alloc_tracker_lock_ = nullptr; |
| Mutex* Locks::allocated_monitor_ids_lock_ = nullptr; |
| Mutex* Locks::allocated_thread_ids_lock_ = nullptr; |
| ReaderWriterMutex* Locks::breakpoint_lock_ = nullptr; |
| ReaderWriterMutex* Locks::classlinker_classes_lock_ = nullptr; |
| Mutex* Locks::custom_tls_lock_ = nullptr; |
| Mutex* Locks::deoptimization_lock_ = nullptr; |
| ReaderWriterMutex* Locks::heap_bitmap_lock_ = nullptr; |
| Mutex* Locks::instrument_entrypoints_lock_ = nullptr; |
| Mutex* Locks::intern_table_lock_ = nullptr; |
| Mutex* Locks::jni_function_table_lock_ = nullptr; |
| Mutex* Locks::jni_libraries_lock_ = nullptr; |
| Mutex* Locks::logging_lock_ = nullptr; |
| Mutex* Locks::modify_ldt_lock_ = nullptr; |
| MutatorMutex* Locks::mutator_lock_ = nullptr; |
| Mutex* Locks::profiler_lock_ = nullptr; |
| ReaderWriterMutex* Locks::verifier_deps_lock_ = nullptr; |
| ReaderWriterMutex* Locks::oat_file_manager_lock_ = nullptr; |
| Mutex* Locks::host_dlopen_handles_lock_ = nullptr; |
| Mutex* Locks::reference_processor_lock_ = nullptr; |
| Mutex* Locks::reference_queue_cleared_references_lock_ = nullptr; |
| Mutex* Locks::reference_queue_finalizer_references_lock_ = nullptr; |
| Mutex* Locks::reference_queue_phantom_references_lock_ = nullptr; |
| Mutex* Locks::reference_queue_soft_references_lock_ = nullptr; |
| Mutex* Locks::reference_queue_weak_references_lock_ = nullptr; |
| Mutex* Locks::runtime_shutdown_lock_ = nullptr; |
| Mutex* Locks::cha_lock_ = nullptr; |
| Mutex* Locks::subtype_check_lock_ = nullptr; |
| Mutex* Locks::thread_list_lock_ = nullptr; |
| ConditionVariable* Locks::thread_exit_cond_ = nullptr; |
| Mutex* Locks::thread_suspend_count_lock_ = nullptr; |
| Mutex* Locks::trace_lock_ = nullptr; |
| Mutex* Locks::unexpected_signal_lock_ = nullptr; |
| Mutex* Locks::user_code_suspension_lock_ = nullptr; |
| Uninterruptible Roles::uninterruptible_; |
| ReaderWriterMutex* Locks::jni_globals_lock_ = nullptr; |
| Mutex* Locks::jni_weak_globals_lock_ = nullptr; |
| ReaderWriterMutex* Locks::dex_lock_ = nullptr; |
| Mutex* Locks::native_debug_interface_lock_ = nullptr; |
| std::vector<BaseMutex*> Locks::expected_mutexes_on_weak_ref_access_; |
| Atomic<const BaseMutex*> Locks::expected_mutexes_on_weak_ref_access_guard_; |
| |
| struct AllMutexData { |
| // A guard for all_mutexes_ that's not a mutex (Mutexes must CAS to acquire and busy wait). |
| Atomic<const BaseMutex*> all_mutexes_guard; |
| // All created mutexes guarded by all_mutexes_guard_. |
| std::set<BaseMutex*>* all_mutexes; |
| AllMutexData() : all_mutexes(nullptr) {} |
| }; |
| static struct AllMutexData gAllMutexData[kAllMutexDataSize]; |
| |
| #if ART_USE_FUTEXES |
| static bool ComputeRelativeTimeSpec(timespec* result_ts, const timespec& lhs, const timespec& rhs) { |
| const int32_t one_sec = 1000 * 1000 * 1000; // one second in nanoseconds. |
| result_ts->tv_sec = lhs.tv_sec - rhs.tv_sec; |
| result_ts->tv_nsec = lhs.tv_nsec - rhs.tv_nsec; |
| if (result_ts->tv_nsec < 0) { |
| result_ts->tv_sec--; |
| result_ts->tv_nsec += one_sec; |
| } else if (result_ts->tv_nsec > one_sec) { |
| result_ts->tv_sec++; |
| result_ts->tv_nsec -= one_sec; |
| } |
| return result_ts->tv_sec < 0; |
| } |
| #endif |
| |
| // Wait for an amount of time that roughly increases in the argument i. |
| // Spin for small arguments and yield/sleep for longer ones. |
| static void BackOff(uint32_t i) { |
| static constexpr uint32_t kSpinMax = 10; |
| static constexpr uint32_t kYieldMax = 20; |
| if (i <= kSpinMax) { |
| // TODO: Esp. in very latency-sensitive cases, consider replacing this with an explicit |
| // test-and-test-and-set loop in the caller. Possibly skip entirely on a uniprocessor. |
| volatile uint32_t x = 0; |
| const uint32_t spin_count = 10 * i; |
| for (uint32_t spin = 0; spin < spin_count; ++spin) { |
| ++x; // Volatile; hence should not be optimized away. |
| } |
| // TODO: Consider adding x86 PAUSE and/or ARM YIELD here. |
| } else if (i <= kYieldMax) { |
| sched_yield(); |
| } else { |
| NanoSleep(1000ull * (i - kYieldMax)); |
| } |
| } |
| |
| class ScopedAllMutexesLock final { |
| public: |
| explicit ScopedAllMutexesLock(const BaseMutex* mutex) : mutex_(mutex) { |
| for (uint32_t i = 0; |
| !gAllMutexData->all_mutexes_guard.CompareAndSetWeakAcquire(nullptr, mutex); |
| ++i) { |
| BackOff(i); |
| } |
| } |
| |
| ~ScopedAllMutexesLock() { |
| DCHECK_EQ(gAllMutexData->all_mutexes_guard.load(std::memory_order_relaxed), mutex_); |
| gAllMutexData->all_mutexes_guard.store(nullptr, std::memory_order_release); |
| } |
| |
| private: |
| const BaseMutex* const mutex_; |
| }; |
| |
| class Locks::ScopedExpectedMutexesOnWeakRefAccessLock final { |
| public: |
| explicit ScopedExpectedMutexesOnWeakRefAccessLock(const BaseMutex* mutex) : mutex_(mutex) { |
| for (uint32_t i = 0; |
| !Locks::expected_mutexes_on_weak_ref_access_guard_.CompareAndSetWeakAcquire(nullptr, |
| mutex); |
| ++i) { |
| BackOff(i); |
| } |
| } |
| |
| ~ScopedExpectedMutexesOnWeakRefAccessLock() { |
| DCHECK_EQ(Locks::expected_mutexes_on_weak_ref_access_guard_.load(std::memory_order_relaxed), |
| mutex_); |
| Locks::expected_mutexes_on_weak_ref_access_guard_.store(nullptr, std::memory_order_release); |
| } |
| |
| private: |
| const BaseMutex* const mutex_; |
| }; |
| |
| // Scoped class that generates events at the beginning and end of lock contention. |
| class ScopedContentionRecorder final : public ValueObject { |
| public: |
| ScopedContentionRecorder(BaseMutex* mutex, uint64_t blocked_tid, uint64_t owner_tid) |
| : mutex_(kLogLockContentions ? mutex : nullptr), |
| blocked_tid_(kLogLockContentions ? blocked_tid : 0), |
| owner_tid_(kLogLockContentions ? owner_tid : 0), |
| start_nano_time_(kLogLockContentions ? NanoTime() : 0) { |
| if (ATRACE_ENABLED()) { |
| std::string msg = StringPrintf("Lock contention on %s (owner tid: %" PRIu64 ")", |
| mutex->GetName(), owner_tid); |
| ATRACE_BEGIN(msg.c_str()); |
| } |
| } |
| |
| ~ScopedContentionRecorder() { |
| ATRACE_END(); |
| if (kLogLockContentions) { |
| uint64_t end_nano_time = NanoTime(); |
| mutex_->RecordContention(blocked_tid_, owner_tid_, end_nano_time - start_nano_time_); |
| } |
| } |
| |
| private: |
| BaseMutex* const mutex_; |
| const uint64_t blocked_tid_; |
| const uint64_t owner_tid_; |
| const uint64_t start_nano_time_; |
| }; |
| |
| BaseMutex::BaseMutex(const char* name, LockLevel level) |
| : name_(name), |
| level_(level), |
| should_respond_to_empty_checkpoint_request_(false) { |
| if (kLogLockContentions) { |
| ScopedAllMutexesLock mu(this); |
| std::set<BaseMutex*>** all_mutexes_ptr = &gAllMutexData->all_mutexes; |
| if (*all_mutexes_ptr == nullptr) { |
| // We leak the global set of all mutexes to avoid ordering issues in global variable |
| // construction/destruction. |
| *all_mutexes_ptr = new std::set<BaseMutex*>(); |
| } |
| (*all_mutexes_ptr)->insert(this); |
| } |
| } |
| |
| BaseMutex::~BaseMutex() { |
| if (kLogLockContentions) { |
| ScopedAllMutexesLock mu(this); |
| gAllMutexData->all_mutexes->erase(this); |
| } |
| } |
| |
| void BaseMutex::DumpAll(std::ostream& os) { |
| if (kLogLockContentions) { |
| os << "Mutex logging:\n"; |
| ScopedAllMutexesLock mu(reinterpret_cast<const BaseMutex*>(-1)); |
| std::set<BaseMutex*>* all_mutexes = gAllMutexData->all_mutexes; |
| if (all_mutexes == nullptr) { |
| // No mutexes have been created yet during at startup. |
| return; |
| } |
| os << "(Contended)\n"; |
| for (const BaseMutex* mutex : *all_mutexes) { |
| if (mutex->HasEverContended()) { |
| mutex->Dump(os); |
| os << "\n"; |
| } |
| } |
| os << "(Never contented)\n"; |
| for (const BaseMutex* mutex : *all_mutexes) { |
| if (!mutex->HasEverContended()) { |
| mutex->Dump(os); |
| os << "\n"; |
| } |
| } |
| } |
| } |
| |
| void BaseMutex::CheckSafeToWait(Thread* self) { |
| if (self == nullptr) { |
| CheckUnattachedThread(level_); |
| return; |
| } |
| if (kDebugLocking) { |
| CHECK(self->GetHeldMutex(level_) == this || level_ == kMonitorLock) |
| << "Waiting on unacquired mutex: " << name_; |
| bool bad_mutexes_held = false; |
| for (int i = kLockLevelCount - 1; i >= 0; --i) { |
| if (i != level_) { |
| BaseMutex* held_mutex = self->GetHeldMutex(static_cast<LockLevel>(i)); |
| // We allow the thread to wait even if the user_code_suspension_lock_ is held so long as we |
| // are some thread's resume_cond_ (level_ == kThreadSuspendCountLock). This just means that |
| // gc or some other internal process is suspending the thread while it is trying to suspend |
| // some other thread. So long as the current thread is not being suspended by a |
| // SuspendReason::kForUserCode (which needs the user_code_suspension_lock_ to clear) this is |
| // fine. |
| if (held_mutex == Locks::user_code_suspension_lock_ && level_ == kThreadSuspendCountLock) { |
| // No thread safety analysis is fine since we have both the user_code_suspension_lock_ |
| // from the line above and the ThreadSuspendCountLock since it is our level_. We use this |
| // lambda to avoid having to annotate the whole function as NO_THREAD_SAFETY_ANALYSIS. |
| auto is_suspending_for_user_code = [self]() NO_THREAD_SAFETY_ANALYSIS { |
| return self->GetUserCodeSuspendCount() != 0; |
| }; |
| if (is_suspending_for_user_code()) { |
| LOG(ERROR) << "Holding \"" << held_mutex->name_ << "\" " |
| << "(level " << LockLevel(i) << ") while performing wait on " |
| << "\"" << name_ << "\" (level " << level_ << ") " |
| << "with SuspendReason::kForUserCode pending suspensions"; |
| bad_mutexes_held = true; |
| } |
| } else if (held_mutex != nullptr) { |
| LOG(ERROR) << "Holding \"" << held_mutex->name_ << "\" " |
| << "(level " << LockLevel(i) << ") while performing wait on " |
| << "\"" << name_ << "\" (level " << level_ << ")"; |
| bad_mutexes_held = true; |
| } |
| } |
| } |
| if (gAborting == 0) { // Avoid recursive aborts. |
| CHECK(!bad_mutexes_held) << this; |
| } |
| } |
| } |
| |
| void BaseMutex::ContentionLogData::AddToWaitTime(uint64_t value) { |
| if (kLogLockContentions) { |
| // Atomically add value to wait_time. |
| wait_time.fetch_add(value, std::memory_order_seq_cst); |
| } |
| } |
| |
| void BaseMutex::RecordContention(uint64_t blocked_tid, |
| uint64_t owner_tid, |
| uint64_t nano_time_blocked) { |
| if (kLogLockContentions) { |
| ContentionLogData* data = contention_log_data_; |
| ++(data->contention_count); |
| data->AddToWaitTime(nano_time_blocked); |
| ContentionLogEntry* log = data->contention_log; |
| // This code is intentionally racy as it is only used for diagnostics. |
| int32_t slot = data->cur_content_log_entry.load(std::memory_order_relaxed); |
| if (log[slot].blocked_tid == blocked_tid && |
| log[slot].owner_tid == blocked_tid) { |
| ++log[slot].count; |
| } else { |
| uint32_t new_slot; |
| do { |
| slot = data->cur_content_log_entry.load(std::memory_order_relaxed); |
| new_slot = (slot + 1) % kContentionLogSize; |
| } while (!data->cur_content_log_entry.CompareAndSetWeakRelaxed(slot, new_slot)); |
| log[new_slot].blocked_tid = blocked_tid; |
| log[new_slot].owner_tid = owner_tid; |
| log[new_slot].count.store(1, std::memory_order_relaxed); |
| } |
| } |
| } |
| |
| void BaseMutex::DumpContention(std::ostream& os) const { |
| if (kLogLockContentions) { |
| const ContentionLogData* data = contention_log_data_; |
| const ContentionLogEntry* log = data->contention_log; |
| uint64_t wait_time = data->wait_time.load(std::memory_order_relaxed); |
| uint32_t contention_count = data->contention_count.load(std::memory_order_relaxed); |
| if (contention_count == 0) { |
| os << "never contended"; |
| } else { |
| os << "contended " << contention_count |
| << " total wait of contender " << PrettyDuration(wait_time) |
| << " average " << PrettyDuration(wait_time / contention_count); |
| SafeMap<uint64_t, size_t> most_common_blocker; |
| SafeMap<uint64_t, size_t> most_common_blocked; |
| for (size_t i = 0; i < kContentionLogSize; ++i) { |
| uint64_t blocked_tid = log[i].blocked_tid; |
| uint64_t owner_tid = log[i].owner_tid; |
| uint32_t count = log[i].count.load(std::memory_order_relaxed); |
| if (count > 0) { |
| auto it = most_common_blocked.find(blocked_tid); |
| if (it != most_common_blocked.end()) { |
| most_common_blocked.Overwrite(blocked_tid, it->second + count); |
| } else { |
| most_common_blocked.Put(blocked_tid, count); |
| } |
| it = most_common_blocker.find(owner_tid); |
| if (it != most_common_blocker.end()) { |
| most_common_blocker.Overwrite(owner_tid, it->second + count); |
| } else { |
| most_common_blocker.Put(owner_tid, count); |
| } |
| } |
| } |
| uint64_t max_tid = 0; |
| size_t max_tid_count = 0; |
| for (const auto& pair : most_common_blocked) { |
| if (pair.second > max_tid_count) { |
| max_tid = pair.first; |
| max_tid_count = pair.second; |
| } |
| } |
| if (max_tid != 0) { |
| os << " sample shows most blocked tid=" << max_tid; |
| } |
| max_tid = 0; |
| max_tid_count = 0; |
| for (const auto& pair : most_common_blocker) { |
| if (pair.second > max_tid_count) { |
| max_tid = pair.first; |
| max_tid_count = pair.second; |
| } |
| } |
| if (max_tid != 0) { |
| os << " sample shows tid=" << max_tid << " owning during this time"; |
| } |
| } |
| } |
| } |
| |
| |
| Mutex::Mutex(const char* name, LockLevel level, bool recursive) |
| : BaseMutex(name, level), exclusive_owner_(0), recursion_count_(0), recursive_(recursive) { |
| #if ART_USE_FUTEXES |
| DCHECK_EQ(0, state_.load(std::memory_order_relaxed)); |
| DCHECK_EQ(0, num_contenders_.load(std::memory_order_relaxed)); |
| #else |
| CHECK_MUTEX_CALL(pthread_mutex_init, (&mutex_, nullptr)); |
| #endif |
| } |
| |
| // Helper to allow checking shutdown while locking for thread safety. |
| static bool IsSafeToCallAbortSafe() { |
| MutexLock mu(Thread::Current(), *Locks::runtime_shutdown_lock_); |
| return Locks::IsSafeToCallAbortRacy(); |
| } |
| |
| Mutex::~Mutex() { |
| bool safe_to_call_abort = Locks::IsSafeToCallAbortRacy(); |
| #if ART_USE_FUTEXES |
| if (state_.load(std::memory_order_relaxed) != 0) { |
| LOG(safe_to_call_abort ? FATAL : WARNING) |
| << "destroying mutex with owner: " << GetExclusiveOwnerTid(); |
| } else { |
| if (GetExclusiveOwnerTid() != 0) { |
| LOG(safe_to_call_abort ? FATAL : WARNING) |
| << "unexpectedly found an owner on unlocked mutex " << name_; |
| } |
| if (num_contenders_.load(std::memory_order_seq_cst) != 0) { |
| LOG(safe_to_call_abort ? FATAL : WARNING) |
| << "unexpectedly found a contender on mutex " << name_; |
| } |
| } |
| #else |
| // We can't use CHECK_MUTEX_CALL here because on shutdown a suspended daemon thread |
| // may still be using locks. |
| int rc = pthread_mutex_destroy(&mutex_); |
| if (rc != 0) { |
| errno = rc; |
| PLOG(safe_to_call_abort ? FATAL : WARNING) |
| << "pthread_mutex_destroy failed for " << name_; |
| } |
| #endif |
| } |
| |
| void Mutex::ExclusiveLock(Thread* self) { |
| DCHECK(self == nullptr || self == Thread::Current()); |
| if (kDebugLocking && !recursive_) { |
| AssertNotHeld(self); |
| } |
| if (!recursive_ || !IsExclusiveHeld(self)) { |
| #if ART_USE_FUTEXES |
| bool done = false; |
| do { |
| int32_t cur_state = state_.load(std::memory_order_relaxed); |
| if (LIKELY(cur_state == 0)) { |
| // Change state from 0 to 1 and impose load/store ordering appropriate for lock acquisition. |
| done = state_.CompareAndSetWeakAcquire(0 /* cur_state */, 1 /* new state */); |
| } else { |
| // Failed to acquire, hang up. |
| ScopedContentionRecorder scr(this, SafeGetTid(self), GetExclusiveOwnerTid()); |
| num_contenders_++; |
| if (UNLIKELY(should_respond_to_empty_checkpoint_request_)) { |
| self->CheckEmptyCheckpointFromMutex(); |
| } |
| if (futex(state_.Address(), FUTEX_WAIT_PRIVATE, 1, nullptr, nullptr, 0) != 0) { |
| // EAGAIN and EINTR both indicate a spurious failure, try again from the beginning. |
| // We don't use TEMP_FAILURE_RETRY so we can intentionally retry to acquire the lock. |
| if ((errno != EAGAIN) && (errno != EINTR)) { |
| PLOG(FATAL) << "futex wait failed for " << name_; |
| } |
| } |
| num_contenders_--; |
| } |
| } while (!done); |
| DCHECK_EQ(state_.load(std::memory_order_relaxed), 1); |
| #else |
| CHECK_MUTEX_CALL(pthread_mutex_lock, (&mutex_)); |
| #endif |
| DCHECK_EQ(GetExclusiveOwnerTid(), 0); |
| exclusive_owner_.store(SafeGetTid(self), std::memory_order_relaxed); |
| RegisterAsLocked(self); |
| } |
| recursion_count_++; |
| if (kDebugLocking) { |
| CHECK(recursion_count_ == 1 || recursive_) << "Unexpected recursion count on mutex: " |
| << name_ << " " << recursion_count_; |
| AssertHeld(self); |
| } |
| } |
| |
| bool Mutex::ExclusiveTryLock(Thread* self) { |
| DCHECK(self == nullptr || self == Thread::Current()); |
| if (kDebugLocking && !recursive_) { |
| AssertNotHeld(self); |
| } |
| if (!recursive_ || !IsExclusiveHeld(self)) { |
| #if ART_USE_FUTEXES |
| bool done = false; |
| do { |
| int32_t cur_state = state_.load(std::memory_order_relaxed); |
| if (cur_state == 0) { |
| // Change state from 0 to 1 and impose load/store ordering appropriate for lock acquisition. |
| done = state_.CompareAndSetWeakAcquire(0 /* cur_state */, 1 /* new state */); |
| } else { |
| return false; |
| } |
| } while (!done); |
| DCHECK_EQ(state_.load(std::memory_order_relaxed), 1); |
| #else |
| int result = pthread_mutex_trylock(&mutex_); |
| if (result == EBUSY) { |
| return false; |
| } |
| if (result != 0) { |
| errno = result; |
| PLOG(FATAL) << "pthread_mutex_trylock failed for " << name_; |
| } |
| #endif |
| DCHECK_EQ(GetExclusiveOwnerTid(), 0); |
| exclusive_owner_.store(SafeGetTid(self), std::memory_order_relaxed); |
| RegisterAsLocked(self); |
| } |
| recursion_count_++; |
| if (kDebugLocking) { |
| CHECK(recursion_count_ == 1 || recursive_) << "Unexpected recursion count on mutex: " |
| << name_ << " " << recursion_count_; |
| AssertHeld(self); |
| } |
| return true; |
| } |
| |
| void Mutex::ExclusiveUnlock(Thread* self) { |
| if (kIsDebugBuild && self != nullptr && self != Thread::Current()) { |
| std::string name1 = "<null>"; |
| std::string name2 = "<null>"; |
| if (self != nullptr) { |
| self->GetThreadName(name1); |
| } |
| if (Thread::Current() != nullptr) { |
| Thread::Current()->GetThreadName(name2); |
| } |
| LOG(FATAL) << GetName() << " level=" << level_ << " self=" << name1 |
| << " Thread::Current()=" << name2; |
| } |
| AssertHeld(self); |
| DCHECK_NE(GetExclusiveOwnerTid(), 0); |
| recursion_count_--; |
| if (!recursive_ || recursion_count_ == 0) { |
| if (kDebugLocking) { |
| CHECK(recursion_count_ == 0 || recursive_) << "Unexpected recursion count on mutex: " |
| << name_ << " " << recursion_count_; |
| } |
| RegisterAsUnlocked(self); |
| #if ART_USE_FUTEXES |
| bool done = false; |
| do { |
| int32_t cur_state = state_.load(std::memory_order_relaxed); |
| if (LIKELY(cur_state == 1)) { |
| // We're no longer the owner. |
| exclusive_owner_.store(0 /* pid */, std::memory_order_relaxed); |
| // Change state to 0 and impose load/store ordering appropriate for lock release. |
| // Note, the relaxed loads below mustn't reorder before the CompareAndSet. |
| // TODO: the ordering here is non-trivial as state is split across 3 fields, fix by placing |
| // a status bit into the state on contention. |
| done = state_.CompareAndSetWeakSequentiallyConsistent(cur_state, 0 /* new state */); |
| if (LIKELY(done)) { // Spurious fail? |
| // Wake a contender. |
| if (UNLIKELY(num_contenders_.load(std::memory_order_seq_cst) > 0)) { |
| futex(state_.Address(), FUTEX_WAKE_PRIVATE, 1, nullptr, nullptr, 0); |
| } |
| } |
| } else { |
| // Logging acquires the logging lock, avoid infinite recursion in that case. |
| if (this != Locks::logging_lock_) { |
| LOG(FATAL) << "Unexpected state_ in unlock " << cur_state << " for " << name_; |
| } else { |
| LogHelper::LogLineLowStack(__FILE__, |
| __LINE__, |
| ::android::base::FATAL_WITHOUT_ABORT, |
| StringPrintf("Unexpected state_ %d in unlock for %s", |
| cur_state, name_).c_str()); |
| _exit(1); |
| } |
| } |
| } while (!done); |
| #else |
| exclusive_owner_.store(0 /* pid */, std::memory_order_relaxed); |
| CHECK_MUTEX_CALL(pthread_mutex_unlock, (&mutex_)); |
| #endif |
| } |
| } |
| |
| void Mutex::Dump(std::ostream& os) const { |
| os << (recursive_ ? "recursive " : "non-recursive ") |
| << name_ |
| << " level=" << static_cast<int>(level_) |
| << " rec=" << recursion_count_ |
| << " owner=" << GetExclusiveOwnerTid() << " "; |
| DumpContention(os); |
| } |
| |
| std::ostream& operator<<(std::ostream& os, const Mutex& mu) { |
| mu.Dump(os); |
| return os; |
| } |
| |
| void Mutex::WakeupToRespondToEmptyCheckpoint() { |
| #if ART_USE_FUTEXES |
| // Wake up all the waiters so they will respond to the emtpy checkpoint. |
| DCHECK(should_respond_to_empty_checkpoint_request_); |
| if (UNLIKELY(num_contenders_.load(std::memory_order_relaxed) > 0)) { |
| futex(state_.Address(), FUTEX_WAKE_PRIVATE, -1, nullptr, nullptr, 0); |
| } |
| #else |
| LOG(FATAL) << "Non futex case isn't supported."; |
| #endif |
| } |
| |
| ReaderWriterMutex::ReaderWriterMutex(const char* name, LockLevel level) |
| : BaseMutex(name, level) |
| #if ART_USE_FUTEXES |
| , state_(0), num_pending_readers_(0), num_pending_writers_(0) |
| #endif |
| { |
| #if !ART_USE_FUTEXES |
| CHECK_MUTEX_CALL(pthread_rwlock_init, (&rwlock_, nullptr)); |
| #endif |
| exclusive_owner_.store(0 /* pid */, std::memory_order_relaxed); |
| } |
| |
| ReaderWriterMutex::~ReaderWriterMutex() { |
| #if ART_USE_FUTEXES |
| CHECK_EQ(state_.load(std::memory_order_relaxed), 0); |
| CHECK_EQ(GetExclusiveOwnerTid(), 0); |
| CHECK_EQ(num_pending_readers_.load(std::memory_order_relaxed), 0); |
| CHECK_EQ(num_pending_writers_.load(std::memory_order_relaxed), 0); |
| #else |
| // We can't use CHECK_MUTEX_CALL here because on shutdown a suspended daemon thread |
| // may still be using locks. |
| int rc = pthread_rwlock_destroy(&rwlock_); |
| if (rc != 0) { |
| errno = rc; |
| bool is_safe_to_call_abort = IsSafeToCallAbortSafe(); |
| PLOG(is_safe_to_call_abort ? FATAL : WARNING) << "pthread_rwlock_destroy failed for " << name_; |
| } |
| #endif |
| } |
| |
| void ReaderWriterMutex::ExclusiveLock(Thread* self) { |
| DCHECK(self == nullptr || self == Thread::Current()); |
| AssertNotExclusiveHeld(self); |
| #if ART_USE_FUTEXES |
| bool done = false; |
| do { |
| int32_t cur_state = state_.load(std::memory_order_relaxed); |
| if (LIKELY(cur_state == 0)) { |
| // Change state from 0 to -1 and impose load/store ordering appropriate for lock acquisition. |
| done = state_.CompareAndSetWeakAcquire(0 /* cur_state*/, -1 /* new state */); |
| } else { |
| // Failed to acquire, hang up. |
| ScopedContentionRecorder scr(this, SafeGetTid(self), GetExclusiveOwnerTid()); |
| ++num_pending_writers_; |
| if (UNLIKELY(should_respond_to_empty_checkpoint_request_)) { |
| self->CheckEmptyCheckpointFromMutex(); |
| } |
| if (futex(state_.Address(), FUTEX_WAIT_PRIVATE, cur_state, nullptr, nullptr, 0) != 0) { |
| // EAGAIN and EINTR both indicate a spurious failure, try again from the beginning. |
| // We don't use TEMP_FAILURE_RETRY so we can intentionally retry to acquire the lock. |
| if ((errno != EAGAIN) && (errno != EINTR)) { |
| PLOG(FATAL) << "futex wait failed for " << name_; |
| } |
| } |
| --num_pending_writers_; |
| } |
| } while (!done); |
| DCHECK_EQ(state_.load(std::memory_order_relaxed), -1); |
| #else |
| CHECK_MUTEX_CALL(pthread_rwlock_wrlock, (&rwlock_)); |
| #endif |
| DCHECK_EQ(GetExclusiveOwnerTid(), 0); |
| exclusive_owner_.store(SafeGetTid(self), std::memory_order_relaxed); |
| RegisterAsLocked(self); |
| AssertExclusiveHeld(self); |
| } |
| |
| void ReaderWriterMutex::ExclusiveUnlock(Thread* self) { |
| DCHECK(self == nullptr || self == Thread::Current()); |
| AssertExclusiveHeld(self); |
| RegisterAsUnlocked(self); |
| DCHECK_NE(GetExclusiveOwnerTid(), 0); |
| #if ART_USE_FUTEXES |
| bool done = false; |
| do { |
| int32_t cur_state = state_.load(std::memory_order_relaxed); |
| if (LIKELY(cur_state == -1)) { |
| // We're no longer the owner. |
| exclusive_owner_.store(0 /* pid */, std::memory_order_relaxed); |
| // Change state from -1 to 0 and impose load/store ordering appropriate for lock release. |
| // Note, the relaxed loads below musn't reorder before the CompareAndSet. |
| // TODO: the ordering here is non-trivial as state is split across 3 fields, fix by placing |
| // a status bit into the state on contention. |
| done = state_.CompareAndSetWeakSequentiallyConsistent(-1 /* cur_state*/, 0 /* new state */); |
| if (LIKELY(done)) { // Weak CAS may fail spuriously. |
| // Wake any waiters. |
| if (UNLIKELY(num_pending_readers_.load(std::memory_order_seq_cst) > 0 || |
| num_pending_writers_.load(std::memory_order_seq_cst) > 0)) { |
| futex(state_.Address(), FUTEX_WAKE_PRIVATE, -1, nullptr, nullptr, 0); |
| } |
| } |
| } else { |
| LOG(FATAL) << "Unexpected state_:" << cur_state << " for " << name_; |
| } |
| } while (!done); |
| #else |
| exclusive_owner_.store(0 /* pid */, std::memory_order_relaxed); |
| CHECK_MUTEX_CALL(pthread_rwlock_unlock, (&rwlock_)); |
| #endif |
| } |
| |
| #if HAVE_TIMED_RWLOCK |
| bool ReaderWriterMutex::ExclusiveLockWithTimeout(Thread* self, int64_t ms, int32_t ns) { |
| DCHECK(self == nullptr || self == Thread::Current()); |
| #if ART_USE_FUTEXES |
| bool done = false; |
| timespec end_abs_ts; |
| InitTimeSpec(true, CLOCK_MONOTONIC, ms, ns, &end_abs_ts); |
| do { |
| int32_t cur_state = state_.load(std::memory_order_relaxed); |
| if (cur_state == 0) { |
| // Change state from 0 to -1 and impose load/store ordering appropriate for lock acquisition. |
| done = state_.CompareAndSetWeakAcquire(0 /* cur_state */, -1 /* new state */); |
| } else { |
| // Failed to acquire, hang up. |
| timespec now_abs_ts; |
| InitTimeSpec(true, CLOCK_MONOTONIC, 0, 0, &now_abs_ts); |
| timespec rel_ts; |
| if (ComputeRelativeTimeSpec(&rel_ts, end_abs_ts, now_abs_ts)) { |
| return false; // Timed out. |
| } |
| ScopedContentionRecorder scr(this, SafeGetTid(self), GetExclusiveOwnerTid()); |
| ++num_pending_writers_; |
| if (UNLIKELY(should_respond_to_empty_checkpoint_request_)) { |
| self->CheckEmptyCheckpointFromMutex(); |
| } |
| if (futex(state_.Address(), FUTEX_WAIT_PRIVATE, cur_state, &rel_ts, nullptr, 0) != 0) { |
| if (errno == ETIMEDOUT) { |
| --num_pending_writers_; |
| return false; // Timed out. |
| } else if ((errno != EAGAIN) && (errno != EINTR)) { |
| // EAGAIN and EINTR both indicate a spurious failure, |
| // recompute the relative time out from now and try again. |
| // We don't use TEMP_FAILURE_RETRY so we can recompute rel_ts; |
| PLOG(FATAL) << "timed futex wait failed for " << name_; |
| } |
| } |
| --num_pending_writers_; |
| } |
| } while (!done); |
| #else |
| timespec ts; |
| InitTimeSpec(true, CLOCK_REALTIME, ms, ns, &ts); |
| int result = pthread_rwlock_timedwrlock(&rwlock_, &ts); |
| if (result == ETIMEDOUT) { |
| return false; |
| } |
| if (result != 0) { |
| errno = result; |
| PLOG(FATAL) << "pthread_rwlock_timedwrlock failed for " << name_; |
| } |
| #endif |
| exclusive_owner_.store(SafeGetTid(self), std::memory_order_relaxed); |
| RegisterAsLocked(self); |
| AssertSharedHeld(self); |
| return true; |
| } |
| #endif |
| |
| #if ART_USE_FUTEXES |
| void ReaderWriterMutex::HandleSharedLockContention(Thread* self, int32_t cur_state) { |
| // Owner holds it exclusively, hang up. |
| ScopedContentionRecorder scr(this, SafeGetTid(self), GetExclusiveOwnerTid()); |
| ++num_pending_readers_; |
| if (UNLIKELY(should_respond_to_empty_checkpoint_request_)) { |
| self->CheckEmptyCheckpointFromMutex(); |
| } |
| if (futex(state_.Address(), FUTEX_WAIT_PRIVATE, cur_state, nullptr, nullptr, 0) != 0) { |
| if (errno != EAGAIN && errno != EINTR) { |
| PLOG(FATAL) << "futex wait failed for " << name_; |
| } |
| } |
| --num_pending_readers_; |
| } |
| #endif |
| |
| bool ReaderWriterMutex::SharedTryLock(Thread* self) { |
| DCHECK(self == nullptr || self == Thread::Current()); |
| #if ART_USE_FUTEXES |
| bool done = false; |
| do { |
| int32_t cur_state = state_.load(std::memory_order_relaxed); |
| if (cur_state >= 0) { |
| // Add as an extra reader and impose load/store ordering appropriate for lock acquisition. |
| done = state_.CompareAndSetWeakAcquire(cur_state, cur_state + 1); |
| } else { |
| // Owner holds it exclusively. |
| return false; |
| } |
| } while (!done); |
| #else |
| int result = pthread_rwlock_tryrdlock(&rwlock_); |
| if (result == EBUSY) { |
| return false; |
| } |
| if (result != 0) { |
| errno = result; |
| PLOG(FATAL) << "pthread_mutex_trylock failed for " << name_; |
| } |
| #endif |
| RegisterAsLocked(self); |
| AssertSharedHeld(self); |
| return true; |
| } |
| |
| bool ReaderWriterMutex::IsSharedHeld(const Thread* self) const { |
| DCHECK(self == nullptr || self == Thread::Current()); |
| bool result; |
| if (UNLIKELY(self == nullptr)) { // Handle unattached threads. |
| result = IsExclusiveHeld(self); // TODO: a better best effort here. |
| } else { |
| result = (self->GetHeldMutex(level_) == this); |
| } |
| return result; |
| } |
| |
| void ReaderWriterMutex::Dump(std::ostream& os) const { |
| os << name_ |
| << " level=" << static_cast<int>(level_) |
| << " owner=" << GetExclusiveOwnerTid() |
| #if ART_USE_FUTEXES |
| << " state=" << state_.load(std::memory_order_seq_cst) |
| << " num_pending_writers=" << num_pending_writers_.load(std::memory_order_seq_cst) |
| << " num_pending_readers=" << num_pending_readers_.load(std::memory_order_seq_cst) |
| #endif |
| << " "; |
| DumpContention(os); |
| } |
| |
| std::ostream& operator<<(std::ostream& os, const ReaderWriterMutex& mu) { |
| mu.Dump(os); |
| return os; |
| } |
| |
| std::ostream& operator<<(std::ostream& os, const MutatorMutex& mu) { |
| mu.Dump(os); |
| return os; |
| } |
| |
| void ReaderWriterMutex::WakeupToRespondToEmptyCheckpoint() { |
| #if ART_USE_FUTEXES |
| // Wake up all the waiters so they will respond to the emtpy checkpoint. |
| DCHECK(should_respond_to_empty_checkpoint_request_); |
| if (UNLIKELY(num_pending_readers_.load(std::memory_order_relaxed) > 0 || |
| num_pending_writers_.load(std::memory_order_relaxed) > 0)) { |
| futex(state_.Address(), FUTEX_WAKE_PRIVATE, -1, nullptr, nullptr, 0); |
| } |
| #else |
| LOG(FATAL) << "Non futex case isn't supported."; |
| #endif |
| } |
| |
| ConditionVariable::ConditionVariable(const char* name, Mutex& guard) |
| : name_(name), guard_(guard) { |
| #if ART_USE_FUTEXES |
| DCHECK_EQ(0, sequence_.load(std::memory_order_relaxed)); |
| num_waiters_ = 0; |
| #else |
| pthread_condattr_t cond_attrs; |
| CHECK_MUTEX_CALL(pthread_condattr_init, (&cond_attrs)); |
| #if !defined(__APPLE__) |
| // Apple doesn't have CLOCK_MONOTONIC or pthread_condattr_setclock. |
| CHECK_MUTEX_CALL(pthread_condattr_setclock, (&cond_attrs, CLOCK_MONOTONIC)); |
| #endif |
| CHECK_MUTEX_CALL(pthread_cond_init, (&cond_, &cond_attrs)); |
| #endif |
| } |
| |
| ConditionVariable::~ConditionVariable() { |
| #if ART_USE_FUTEXES |
| if (num_waiters_!= 0) { |
| bool is_safe_to_call_abort = IsSafeToCallAbortSafe(); |
| LOG(is_safe_to_call_abort ? FATAL : WARNING) |
| << "ConditionVariable::~ConditionVariable for " << name_ |
| << " called with " << num_waiters_ << " waiters."; |
| } |
| #else |
| // We can't use CHECK_MUTEX_CALL here because on shutdown a suspended daemon thread |
| // may still be using condition variables. |
| int rc = pthread_cond_destroy(&cond_); |
| if (rc != 0) { |
| errno = rc; |
| bool is_safe_to_call_abort = IsSafeToCallAbortSafe(); |
| PLOG(is_safe_to_call_abort ? FATAL : WARNING) << "pthread_cond_destroy failed for " << name_; |
| } |
| #endif |
| } |
| |
| void ConditionVariable::Broadcast(Thread* self) { |
| DCHECK(self == nullptr || self == Thread::Current()); |
| // TODO: enable below, there's a race in thread creation that causes false failures currently. |
| // guard_.AssertExclusiveHeld(self); |
| DCHECK_EQ(guard_.GetExclusiveOwnerTid(), SafeGetTid(self)); |
| #if ART_USE_FUTEXES |
| RequeueWaiters(std::numeric_limits<int32_t>::max()); |
| #else |
| CHECK_MUTEX_CALL(pthread_cond_broadcast, (&cond_)); |
| #endif |
| } |
| |
| #if ART_USE_FUTEXES |
| void ConditionVariable::RequeueWaiters(int32_t count) { |
| if (num_waiters_ > 0) { |
| sequence_++; // Indicate a signal occurred. |
| // Move waiters from the condition variable's futex to the guard's futex, |
| // so that they will be woken up when the mutex is released. |
| bool done = futex(sequence_.Address(), |
| FUTEX_REQUEUE_PRIVATE, |
| /* Threads to wake */ 0, |
| /* Threads to requeue*/ reinterpret_cast<const timespec*>(count), |
| guard_.state_.Address(), |
| 0) != -1; |
| if (!done && errno != EAGAIN && errno != EINTR) { |
| PLOG(FATAL) << "futex requeue failed for " << name_; |
| } |
| } |
| } |
| #endif |
| |
| |
| void ConditionVariable::Signal(Thread* self) { |
| DCHECK(self == nullptr || self == Thread::Current()); |
| guard_.AssertExclusiveHeld(self); |
| #if ART_USE_FUTEXES |
| RequeueWaiters(1); |
| #else |
| CHECK_MUTEX_CALL(pthread_cond_signal, (&cond_)); |
| #endif |
| } |
| |
| void ConditionVariable::Wait(Thread* self) { |
| guard_.CheckSafeToWait(self); |
| WaitHoldingLocks(self); |
| } |
| |
| void ConditionVariable::WaitHoldingLocks(Thread* self) { |
| DCHECK(self == nullptr || self == Thread::Current()); |
| guard_.AssertExclusiveHeld(self); |
| unsigned int old_recursion_count = guard_.recursion_count_; |
| #if ART_USE_FUTEXES |
| num_waiters_++; |
| // Ensure the Mutex is contended so that requeued threads are awoken. |
| guard_.num_contenders_++; |
| guard_.recursion_count_ = 1; |
| int32_t cur_sequence = sequence_.load(std::memory_order_relaxed); |
| guard_.ExclusiveUnlock(self); |
| if (futex(sequence_.Address(), FUTEX_WAIT_PRIVATE, cur_sequence, nullptr, nullptr, 0) != 0) { |
| // Futex failed, check it is an expected error. |
| // EAGAIN == EWOULDBLK, so we let the caller try again. |
| // EINTR implies a signal was sent to this thread. |
| if ((errno != EINTR) && (errno != EAGAIN)) { |
| PLOG(FATAL) << "futex wait failed for " << name_; |
| } |
| } |
| if (self != nullptr) { |
| JNIEnvExt* const env = self->GetJniEnv(); |
| if (UNLIKELY(env != nullptr && env->IsRuntimeDeleted())) { |
| CHECK(self->IsDaemon()); |
| // If the runtime has been deleted, then we cannot proceed. Just sleep forever. This may |
| // occur for user daemon threads that get a spurious wakeup. This occurs for test 132 with |
| // --host and --gdb. |
| // After we wake up, the runtime may have been shutdown, which means that this condition may |
| // have been deleted. It is not safe to retry the wait. |
| SleepForever(); |
| } |
| } |
| guard_.ExclusiveLock(self); |
| CHECK_GE(num_waiters_, 0); |
| num_waiters_--; |
| // We awoke and so no longer require awakes from the guard_'s unlock. |
| CHECK_GE(guard_.num_contenders_.load(std::memory_order_relaxed), 0); |
| guard_.num_contenders_--; |
| #else |
| pid_t old_owner = guard_.GetExclusiveOwnerTid(); |
| guard_.exclusive_owner_.store(0 /* pid */, std::memory_order_relaxed); |
| guard_.recursion_count_ = 0; |
| CHECK_MUTEX_CALL(pthread_cond_wait, (&cond_, &guard_.mutex_)); |
| guard_.exclusive_owner_.store(old_owner, std::memory_order_relaxed); |
| #endif |
| guard_.recursion_count_ = old_recursion_count; |
| } |
| |
| bool ConditionVariable::TimedWait(Thread* self, int64_t ms, int32_t ns) { |
| DCHECK(self == nullptr || self == Thread::Current()); |
| bool timed_out = false; |
| guard_.AssertExclusiveHeld(self); |
| guard_.CheckSafeToWait(self); |
| unsigned int old_recursion_count = guard_.recursion_count_; |
| #if ART_USE_FUTEXES |
| timespec rel_ts; |
| InitTimeSpec(false, CLOCK_REALTIME, ms, ns, &rel_ts); |
| num_waiters_++; |
| // Ensure the Mutex is contended so that requeued threads are awoken. |
| guard_.num_contenders_++; |
| guard_.recursion_count_ = 1; |
| int32_t cur_sequence = sequence_.load(std::memory_order_relaxed); |
| guard_.ExclusiveUnlock(self); |
| if (futex(sequence_.Address(), FUTEX_WAIT_PRIVATE, cur_sequence, &rel_ts, nullptr, 0) != 0) { |
| if (errno == ETIMEDOUT) { |
| // Timed out we're done. |
| timed_out = true; |
| } else if ((errno == EAGAIN) || (errno == EINTR)) { |
| // A signal or ConditionVariable::Signal/Broadcast has come in. |
| } else { |
| PLOG(FATAL) << "timed futex wait failed for " << name_; |
| } |
| } |
| guard_.ExclusiveLock(self); |
| CHECK_GE(num_waiters_, 0); |
| num_waiters_--; |
| // We awoke and so no longer require awakes from the guard_'s unlock. |
| CHECK_GE(guard_.num_contenders_.load(std::memory_order_relaxed), 0); |
| guard_.num_contenders_--; |
| #else |
| #if !defined(__APPLE__) |
| int clock = CLOCK_MONOTONIC; |
| #else |
| int clock = CLOCK_REALTIME; |
| #endif |
| pid_t old_owner = guard_.GetExclusiveOwnerTid(); |
| guard_.exclusive_owner_.store(0 /* pid */, std::memory_order_relaxed); |
| guard_.recursion_count_ = 0; |
| timespec ts; |
| InitTimeSpec(true, clock, ms, ns, &ts); |
| int rc; |
| while ((rc = pthread_cond_timedwait(&cond_, &guard_.mutex_, &ts)) == EINTR) { |
| continue; |
| } |
| |
| if (rc == ETIMEDOUT) { |
| timed_out = true; |
| } else if (rc != 0) { |
| errno = rc; |
| PLOG(FATAL) << "TimedWait failed for " << name_; |
| } |
| guard_.exclusive_owner_.store(old_owner, std::memory_order_relaxed); |
| #endif |
| guard_.recursion_count_ = old_recursion_count; |
| return timed_out; |
| } |
| |
| void Locks::Init() { |
| if (logging_lock_ != nullptr) { |
| // Already initialized. |
| if (kRuntimeISA == InstructionSet::kX86 || kRuntimeISA == InstructionSet::kX86_64) { |
| DCHECK(modify_ldt_lock_ != nullptr); |
| } else { |
| DCHECK(modify_ldt_lock_ == nullptr); |
| } |
| DCHECK(abort_lock_ != nullptr); |
| DCHECK(alloc_tracker_lock_ != nullptr); |
| DCHECK(allocated_monitor_ids_lock_ != nullptr); |
| DCHECK(allocated_thread_ids_lock_ != nullptr); |
| DCHECK(breakpoint_lock_ != nullptr); |
| DCHECK(classlinker_classes_lock_ != nullptr); |
| DCHECK(custom_tls_lock_ != nullptr); |
| DCHECK(deoptimization_lock_ != nullptr); |
| DCHECK(heap_bitmap_lock_ != nullptr); |
| DCHECK(oat_file_manager_lock_ != nullptr); |
| DCHECK(verifier_deps_lock_ != nullptr); |
| DCHECK(host_dlopen_handles_lock_ != nullptr); |
| DCHECK(intern_table_lock_ != nullptr); |
| DCHECK(jni_function_table_lock_ != nullptr); |
| DCHECK(jni_libraries_lock_ != nullptr); |
| DCHECK(logging_lock_ != nullptr); |
| DCHECK(mutator_lock_ != nullptr); |
| DCHECK(profiler_lock_ != nullptr); |
| DCHECK(cha_lock_ != nullptr); |
| DCHECK(subtype_check_lock_ != nullptr); |
| DCHECK(thread_list_lock_ != nullptr); |
| DCHECK(thread_suspend_count_lock_ != nullptr); |
| DCHECK(trace_lock_ != nullptr); |
| DCHECK(unexpected_signal_lock_ != nullptr); |
| DCHECK(user_code_suspension_lock_ != nullptr); |
| DCHECK(dex_lock_ != nullptr); |
| DCHECK(native_debug_interface_lock_ != nullptr); |
| } else { |
| // Create global locks in level order from highest lock level to lowest. |
| LockLevel current_lock_level = kInstrumentEntrypointsLock; |
| DCHECK(instrument_entrypoints_lock_ == nullptr); |
| instrument_entrypoints_lock_ = new Mutex("instrument entrypoint lock", current_lock_level); |
| |
| #define UPDATE_CURRENT_LOCK_LEVEL(new_level) \ |
| if ((new_level) >= current_lock_level) { \ |
| /* Do not use CHECKs or FATAL here, abort_lock_ is not setup yet. */ \ |
| fprintf(stderr, "New local level %d is not less than current level %d\n", \ |
| new_level, current_lock_level); \ |
| exit(1); \ |
| } \ |
| current_lock_level = new_level; |
| |
| UPDATE_CURRENT_LOCK_LEVEL(kUserCodeSuspensionLock); |
| DCHECK(user_code_suspension_lock_ == nullptr); |
| user_code_suspension_lock_ = new Mutex("user code suspension lock", current_lock_level); |
| |
| UPDATE_CURRENT_LOCK_LEVEL(kMutatorLock); |
| DCHECK(mutator_lock_ == nullptr); |
| mutator_lock_ = new MutatorMutex("mutator lock", current_lock_level); |
| |
| UPDATE_CURRENT_LOCK_LEVEL(kHeapBitmapLock); |
| DCHECK(heap_bitmap_lock_ == nullptr); |
| heap_bitmap_lock_ = new ReaderWriterMutex("heap bitmap lock", current_lock_level); |
| |
| UPDATE_CURRENT_LOCK_LEVEL(kTraceLock); |
| DCHECK(trace_lock_ == nullptr); |
| trace_lock_ = new Mutex("trace lock", current_lock_level); |
| |
| UPDATE_CURRENT_LOCK_LEVEL(kRuntimeShutdownLock); |
| DCHECK(runtime_shutdown_lock_ == nullptr); |
| runtime_shutdown_lock_ = new Mutex("runtime shutdown lock", current_lock_level); |
| |
| UPDATE_CURRENT_LOCK_LEVEL(kProfilerLock); |
| DCHECK(profiler_lock_ == nullptr); |
| profiler_lock_ = new Mutex("profiler lock", current_lock_level); |
| |
| UPDATE_CURRENT_LOCK_LEVEL(kDeoptimizationLock); |
| DCHECK(deoptimization_lock_ == nullptr); |
| deoptimization_lock_ = new Mutex("Deoptimization lock", current_lock_level); |
| |
| UPDATE_CURRENT_LOCK_LEVEL(kAllocTrackerLock); |
| DCHECK(alloc_tracker_lock_ == nullptr); |
| alloc_tracker_lock_ = new Mutex("AllocTracker lock", current_lock_level); |
| |
| UPDATE_CURRENT_LOCK_LEVEL(kThreadListLock); |
| DCHECK(thread_list_lock_ == nullptr); |
| thread_list_lock_ = new Mutex("thread list lock", current_lock_level); |
| |
| UPDATE_CURRENT_LOCK_LEVEL(kJniLoadLibraryLock); |
| DCHECK(jni_libraries_lock_ == nullptr); |
| jni_libraries_lock_ = new Mutex("JNI shared libraries map lock", current_lock_level); |
| |
| UPDATE_CURRENT_LOCK_LEVEL(kBreakpointLock); |
| DCHECK(breakpoint_lock_ == nullptr); |
| breakpoint_lock_ = new ReaderWriterMutex("breakpoint lock", current_lock_level); |
| |
| UPDATE_CURRENT_LOCK_LEVEL(kSubtypeCheckLock); |
| DCHECK(subtype_check_lock_ == nullptr); |
| subtype_check_lock_ = new Mutex("SubtypeCheck lock", current_lock_level); |
| |
| UPDATE_CURRENT_LOCK_LEVEL(kClassLinkerClassesLock); |
| DCHECK(classlinker_classes_lock_ == nullptr); |
| classlinker_classes_lock_ = new ReaderWriterMutex("ClassLinker classes lock", |
| current_lock_level); |
| |
| UPDATE_CURRENT_LOCK_LEVEL(kMonitorPoolLock); |
| DCHECK(allocated_monitor_ids_lock_ == nullptr); |
| allocated_monitor_ids_lock_ = new Mutex("allocated monitor ids lock", current_lock_level); |
| |
| UPDATE_CURRENT_LOCK_LEVEL(kAllocatedThreadIdsLock); |
| DCHECK(allocated_thread_ids_lock_ == nullptr); |
| allocated_thread_ids_lock_ = new Mutex("allocated thread ids lock", current_lock_level); |
| |
| if (kRuntimeISA == InstructionSet::kX86 || kRuntimeISA == InstructionSet::kX86_64) { |
| UPDATE_CURRENT_LOCK_LEVEL(kModifyLdtLock); |
| DCHECK(modify_ldt_lock_ == nullptr); |
| modify_ldt_lock_ = new Mutex("modify_ldt lock", current_lock_level); |
| } |
| |
| UPDATE_CURRENT_LOCK_LEVEL(kDexLock); |
| DCHECK(dex_lock_ == nullptr); |
| dex_lock_ = new ReaderWriterMutex("ClassLinker dex lock", current_lock_level); |
| |
| UPDATE_CURRENT_LOCK_LEVEL(kOatFileManagerLock); |
| DCHECK(oat_file_manager_lock_ == nullptr); |
| oat_file_manager_lock_ = new ReaderWriterMutex("OatFile manager lock", current_lock_level); |
| |
| UPDATE_CURRENT_LOCK_LEVEL(kVerifierDepsLock); |
| DCHECK(verifier_deps_lock_ == nullptr); |
| verifier_deps_lock_ = new ReaderWriterMutex("verifier deps lock", current_lock_level); |
| |
| UPDATE_CURRENT_LOCK_LEVEL(kHostDlOpenHandlesLock); |
| DCHECK(host_dlopen_handles_lock_ == nullptr); |
| host_dlopen_handles_lock_ = new Mutex("host dlopen handles lock", current_lock_level); |
| |
| UPDATE_CURRENT_LOCK_LEVEL(kInternTableLock); |
| DCHECK(intern_table_lock_ == nullptr); |
| intern_table_lock_ = new Mutex("InternTable lock", current_lock_level); |
| |
| UPDATE_CURRENT_LOCK_LEVEL(kReferenceProcessorLock); |
| DCHECK(reference_processor_lock_ == nullptr); |
| reference_processor_lock_ = new Mutex("ReferenceProcessor lock", current_lock_level); |
| |
| UPDATE_CURRENT_LOCK_LEVEL(kReferenceQueueClearedReferencesLock); |
| DCHECK(reference_queue_cleared_references_lock_ == nullptr); |
| reference_queue_cleared_references_lock_ = new Mutex("ReferenceQueue cleared references lock", current_lock_level); |
| |
| UPDATE_CURRENT_LOCK_LEVEL(kReferenceQueueWeakReferencesLock); |
| DCHECK(reference_queue_weak_references_lock_ == nullptr); |
| reference_queue_weak_references_lock_ = new Mutex("ReferenceQueue cleared references lock", current_lock_level); |
| |
| UPDATE_CURRENT_LOCK_LEVEL(kReferenceQueueFinalizerReferencesLock); |
| DCHECK(reference_queue_finalizer_references_lock_ == nullptr); |
| reference_queue_finalizer_references_lock_ = new Mutex("ReferenceQueue finalizer references lock", current_lock_level); |
| |
| UPDATE_CURRENT_LOCK_LEVEL(kReferenceQueuePhantomReferencesLock); |
| DCHECK(reference_queue_phantom_references_lock_ == nullptr); |
| reference_queue_phantom_references_lock_ = new Mutex("ReferenceQueue phantom references lock", current_lock_level); |
| |
| UPDATE_CURRENT_LOCK_LEVEL(kReferenceQueueSoftReferencesLock); |
| DCHECK(reference_queue_soft_references_lock_ == nullptr); |
| reference_queue_soft_references_lock_ = new Mutex("ReferenceQueue soft references lock", current_lock_level); |
| |
| UPDATE_CURRENT_LOCK_LEVEL(kJniGlobalsLock); |
| DCHECK(jni_globals_lock_ == nullptr); |
| jni_globals_lock_ = |
| new ReaderWriterMutex("JNI global reference table lock", current_lock_level); |
| |
| UPDATE_CURRENT_LOCK_LEVEL(kJniWeakGlobalsLock); |
| DCHECK(jni_weak_globals_lock_ == nullptr); |
| jni_weak_globals_lock_ = new Mutex("JNI weak global reference table lock", current_lock_level); |
| |
| UPDATE_CURRENT_LOCK_LEVEL(kJniFunctionTableLock); |
| DCHECK(jni_function_table_lock_ == nullptr); |
| jni_function_table_lock_ = new Mutex("JNI function table lock", current_lock_level); |
| |
| UPDATE_CURRENT_LOCK_LEVEL(kCustomTlsLock); |
| DCHECK(custom_tls_lock_ == nullptr); |
| custom_tls_lock_ = new Mutex("Thread::custom_tls_ lock", current_lock_level); |
| |
| UPDATE_CURRENT_LOCK_LEVEL(kCHALock); |
| DCHECK(cha_lock_ == nullptr); |
| cha_lock_ = new Mutex("CHA lock", current_lock_level); |
| |
| UPDATE_CURRENT_LOCK_LEVEL(kNativeDebugInterfaceLock); |
| DCHECK(native_debug_interface_lock_ == nullptr); |
| native_debug_interface_lock_ = new Mutex("Native debug interface lock", current_lock_level); |
| |
| UPDATE_CURRENT_LOCK_LEVEL(kAbortLock); |
| DCHECK(abort_lock_ == nullptr); |
| abort_lock_ = new Mutex("abort lock", current_lock_level, true); |
| |
| UPDATE_CURRENT_LOCK_LEVEL(kThreadSuspendCountLock); |
| DCHECK(thread_suspend_count_lock_ == nullptr); |
| thread_suspend_count_lock_ = new Mutex("thread suspend count lock", current_lock_level); |
| |
| UPDATE_CURRENT_LOCK_LEVEL(kUnexpectedSignalLock); |
| DCHECK(unexpected_signal_lock_ == nullptr); |
| unexpected_signal_lock_ = new Mutex("unexpected signal lock", current_lock_level, true); |
| |
| UPDATE_CURRENT_LOCK_LEVEL(kLoggingLock); |
| DCHECK(logging_lock_ == nullptr); |
| logging_lock_ = new Mutex("logging lock", current_lock_level, true); |
| |
| #undef UPDATE_CURRENT_LOCK_LEVEL |
| |
| // List of mutexes that we may hold when accessing a weak ref. |
| AddToExpectedMutexesOnWeakRefAccess(dex_lock_, /*need_lock=*/ false); |
| AddToExpectedMutexesOnWeakRefAccess(classlinker_classes_lock_, /*need_lock=*/ false); |
| AddToExpectedMutexesOnWeakRefAccess(jni_libraries_lock_, /*need_lock=*/ false); |
| |
| InitConditions(); |
| } |
| } |
| |
| void Locks::InitConditions() { |
| thread_exit_cond_ = new ConditionVariable("thread exit condition variable", *thread_list_lock_); |
| } |
| |
| void Locks::SetClientCallback(ClientCallback* safe_to_call_abort_cb) { |
| safe_to_call_abort_callback.store(safe_to_call_abort_cb, std::memory_order_release); |
| } |
| |
| // Helper to allow checking shutdown while ignoring locking requirements. |
| bool Locks::IsSafeToCallAbortRacy() { |
| Locks::ClientCallback* safe_to_call_abort_cb = |
| safe_to_call_abort_callback.load(std::memory_order_acquire); |
| return safe_to_call_abort_cb != nullptr && safe_to_call_abort_cb(); |
| } |
| |
| void Locks::AddToExpectedMutexesOnWeakRefAccess(BaseMutex* mutex, bool need_lock) { |
| if (need_lock) { |
| ScopedExpectedMutexesOnWeakRefAccessLock mu(mutex); |
| mutex->SetShouldRespondToEmptyCheckpointRequest(true); |
| expected_mutexes_on_weak_ref_access_.push_back(mutex); |
| } else { |
| mutex->SetShouldRespondToEmptyCheckpointRequest(true); |
| expected_mutexes_on_weak_ref_access_.push_back(mutex); |
| } |
| } |
| |
| void Locks::RemoveFromExpectedMutexesOnWeakRefAccess(BaseMutex* mutex, bool need_lock) { |
| if (need_lock) { |
| ScopedExpectedMutexesOnWeakRefAccessLock mu(mutex); |
| mutex->SetShouldRespondToEmptyCheckpointRequest(false); |
| std::vector<BaseMutex*>& list = expected_mutexes_on_weak_ref_access_; |
| auto it = std::find(list.begin(), list.end(), mutex); |
| DCHECK(it != list.end()); |
| list.erase(it); |
| } else { |
| mutex->SetShouldRespondToEmptyCheckpointRequest(false); |
| std::vector<BaseMutex*>& list = expected_mutexes_on_weak_ref_access_; |
| auto it = std::find(list.begin(), list.end(), mutex); |
| DCHECK(it != list.end()); |
| list.erase(it); |
| } |
| } |
| |
| bool Locks::IsExpectedOnWeakRefAccess(BaseMutex* mutex) { |
| ScopedExpectedMutexesOnWeakRefAccessLock mu(mutex); |
| std::vector<BaseMutex*>& list = expected_mutexes_on_weak_ref_access_; |
| return std::find(list.begin(), list.end(), mutex) != list.end(); |
| } |
| |
| } // namespace art |